Membrane Separation Technology for Water Treatment in Upstream Oil & Gas Operations

James Robinson, 2016

Membrane Separation Technology for Water Treatment in Upstream Oil & Gas Operations

James Robinson, P.E.April 20, 2016

Semi-Annual Water & Wastewater Short Course: Issues, Challenges, Solutions & New Technologies

Global Petroleum Research Institute (GPRI) - Texas A&M Department of Petroleum Engineering


James Robinson, P.E.

Experience • Water Treatment

Engineering Advisor• Chevron (2011-2015)• BP (2000-2009)

• Water Management Engineering Consultant• Oxidane Engineering (2009-2011, 2015-present)• Cypress Engineering (1991-2000)

Professional • Professional Engineer• Society of Petroleum Engineers• Produced Water SocietyEducation • B.S. in Civil Engineering (1990)

Louisiana State University• M.S. in Engineering (1992)

Rice UniversityContact • [email protected]• (281) 384-3327

mailto:[email protected]?subject=


Outline

• Introduction / Overview

• Composition / Characterization

• Seawater,

• Produced Water

• Quantities

• Produced Water Disposition

• Water Treatment Process Design

• Onshore Scenarios

• Offshore Scenarios


Terms used• PW - produced water

• BPD - barrels per day

• MF - microfiltration membrane

• NF - nanofiltration membrane

• SRM - sulfate removal membrane

• RO - reverse osmosis membrane

• TSS - total suspended solids

• TDS - total dissolved solids

• TPH - total petroleum hydrocarbons (non-soluble organics)

• TOG - total oil & grease (soluble & non-soluble organics)

• EOR - enhanced oil recovery

• ASP - alkali, surfactant, polymer (Chemical-EOR)

• IX - ion exchange (softening)


Composition / Characterization• Primary Parameters:

• Suspended Solids

• Dispersed Oil (hydrocarbon droplets not soluble in water)

• Additional Parameters (Depending on water re-use / recycling opportunity):

• Dissolved solids:

• Primary cations: Na+, K+, Ca2+, Mg2+,

• Primary anions: Cl-, SO42-, bicarbonate

• Additional Indicators: Hardness, Alkalinity

• Other parameters of interest: barium, strontium, iron, boron, silica, acetate

• Dissolved Oil (hydrocarbon compounds soluble in water)

• Dissolved Oxygen

• Residual water treatment chemicals

• Residual chlorine (from biological control)

• Residual sulfite (from oxygen scavenger)


Seawater Composition


Primary Produced Water Constituents

Produced Water

Organic Inorganic

Insoluble SolubleInsoluble Soluble

Cations Anions

Monovalent Multivalent

Produced Water

Organic Inorganic


Cations Anions



Primary Produced Water Constituents to remove for Produced Water Re-Injection (PWRI)

Produced Water

Organic Inorganic


Cations Anions


TPH TSS

MF


Primary Produced Water Constituents to remove for Offshore Discharge

Produced Water

Organic Inorganic


Cations Anions


Produced Water

Organic Inorganic


Cations Anions


TPH

TOG


Primary Produced Water Constituents to remove for Chemical-EOR Flood

Produced Water

Organic Inorganic


Cations Anions


Produced Water

Organic Inorganic


Cations Anions


TSSTPH

TOG

HardnessNF

MF


Primary Produced Water Constituents to remove for Low Salinity Waterflood & Beneficial Reuse

Produced Water

Organic Inorganic


Cations Anions


Produced Water

Organic Inorganic


Cations Anions


TSSTPH

TOG

TDS

MF

RO


Quantities• Seawater Injection

• Many offshore developments inject ~1 to 2 bbls seawater per bbl fluid (oil & water) produced

• Typical offshore injection wells are designed to injection ~10,000 to 30,000 BPD seawater

• Several large offshore facilities inject ~500,000 BPD seawater

• Produced Water

• On average, 8 bbls water produced per bbl oil worldwide

• Some mature field are economically operated at up to 98% water cut (50 bbls water produced / bbl oil produced)

• U.S. produced water for all oil & gas is ~21 billion bbls (882 billion gals) (Source: Clark and Veil, 2009)

• Of that amount, flow-back water from hydraulic fracturing of unconventional wells in the US is ~1.2 billion bbls (50 billion gals; 5.7% of all produced water)


Produced Water Disposition

• Onshore

~95% PW is re-injected into injection wells (either water flood or disposal)

~5% PW is treated for beneficial reuse (generally, where disposal capacity is limited or where water is scarce)

• Offshore

~85% PW is treated for discharge into the sea (disposal overboard)

~15% PW is re-injected into injection wells (either water flood or disposal; generally, where required by regulation)


Water Treatment Process Design

• Water Balance & Water Management Plan

• Source Water (Influent) Selection & Water Quality Characterization

• Operational Conditions, Constraints & Priorities

• Treated Effluent Use, Disposal & Water Quality Specifications

• Optimize Water Management (Reduce, Reuse & Recycle)

• Technology Selection

• Integration of multi-technology process (pre-treatment processes)


Water Balance & Water Management Plan• Water Balance

• Determine Water Needs

• Identify Potential Water Sources and Capacities

• Determine Wastewater Streams

• Identify Wastewater Disposal Options and Capacities

• Optimize Water Management

• Identify Water Efficiency / Reduction Opportunities

• Identify Water Reuse Opportunities (with minimal or no water treatment)

• Identify Water Recycling Opportunities (with significant water treatment)

• Develop a Water Management Plan:

• Meets water needs

• Has available/sustainable water sources

• Ensures adequate wastewater disposal capacity / reliability

• Considers timing of water needs, water sources, wastewater streams

• Maximizes economic benefits of water reduction, reuse & recycling

• Minimized environmental impacts on water supplies and environments where wastewater is disposed


Treatment Conditions, Constraints & Priorities

• Water Quality & Quantity variability

• Onshore vs Offshore

• Manned vs Un-manned

• Manually Controlled vs Remote Controlled vs Automated

• CAPEX vs OPEX

• Reliability / Redundancy

• Project life-cycle, re-deployment


Primary Options for Produced Water Disposition• Reuse (minimal or no treatment)

• Waterflood

• Recycling (requires treatment)

• Steam Flood EOR

• Low Salinity Waterflood EOR

• Chemical-EOR Flood

• Beneficial Reuse

• Agriculture

• Irrigation

• Livestock

• Stream flow restoration

• Groundwater Aquifer restoration

• Disposal

• Deep well injection

• Surface discharge (offshore discharge)

• Evaporation


Technology Selection

• Select the most appropriate (economical / reliable / compact) technology(s) that will achieve the Treated Effluent Specifications, given the Source Water Characterization and Operational Conditions, Constraints & Priorities

• A multi-technology process is often required (pre-treatment, etc.)


Examples of Onshore Scenarios (Generic/Hypothetical)

• Onshore Produced Water Treatment Process (Ceramic MF & RO)

• Onshore Chemical-EOR Waterflood Process (MF & NF)

• Onshore Gas Gathering and Processing Plant Wastewater Recycling Process (MF & RO)


Onshore Produced Water Treatment Process (Ceramic MF & RO)

Scenario: Beneficial reuse of produced water used as alternative to water disposal in wells due to limited water disposal capacity and reliability; Ceramic MF used as a pre-treatment for IX and RO

Influent: Produced Water (formation water plus re-produced steam)

Influent Water Characterization:Flowrate: 50,000 BPDTDS: 6,000 mg/LTSS: 10 mg/LTPH: 100 mg/L (after primary oil/water separation)

Treated Effluent Use: Discharge to Surface Wetlands

Treated Effluent Specification:TDS: < 500 mg/LTPH: < 1 mg/L(additional treated effluent specification include organic compounds and metals)

Process:Primary

Oil/Water Separation

PW Gravity Separation IX WetlandsRO

Surface Discharge to River

Gas Flotation

Walnut Shell Filter

Ceramic MF


Onshore Produced Water Treatment Process

Source: Veolia


Onshore Chemical-EOR Waterflood Process (Ceramic MF & NF)

Scenario: Ceramic MF used as pretreatment for IX and NF; NF used for PW softening for mixing with ASP for injection into wells for enhanced oil production

Influents:Produced Water (formation water)

Influent Water Characterization:Flowrate: 50,000 BPDTDS: 2,500 mg/LTSS: 10 mg/LTPH: 100 mg/L (after primary oil/water separation)

Treated Effluent Use: Produced Water Recycling for Mixing with ASP for polymer flood

Treated Effluent Specifications:For mixing with ASP and then injection into wells:

Hardness: < 30 mg/LTPH: < 1 mg/L (feed into NF)TSS: < 1 mg/L

Process:Primary

Oil/Water Separation

PW Gravity Separation IX ASP

MixingNF Injection Wells

Gas Flotation

Walnut Shell Filter

Ceramic MF


Chemical-EOR: Enhanced oil recovery by ASP (alkali, surfactant & polymer) flooding

natural gas

oil

water

NF


Onshore Gas Gathering and Processing Plant Wastewater Recycling Process (MF & RO)Scenario: Wastewater recycling is an alternative to disposal in wells due to limited well disposal capacity and reliability

Influents:Produced Water (formation water); (oily, saline & TSS)Utility / Process Area Water (UPA: wash water) (oily, non-saline, TSS) IX Brine (non-oily, saline, no-TSS)Cooling Tower Blowdown (CBD: non-oily, saline, no-TSS)Steam Boiler Blowdown (BBD: non-oily, saline, no-TSS)

PW Water Characterization:Flowrate: 1,900 m3/d (12,000 BPD)TDS: 5,000 mg/LTSS: 10 mg/LTPH: 100 mg/L (after primary oil/water separation)

Treated Effluent Use: Produced Water Recycling for feed to Steam Boilers

Treated Effluent Specifications:For reuse in Steam Boilers:

Hardness: < 0.5 mg/L (feed into steam boilers)TPH: < 1 mg/L (feed into NF)TSS: < 1 mg/L

Technology Selection: • PW treatment with gas flotation & nutshell filtration prior to wastewater recycling process• Concentrated brine streams (CBD, BBD, IX Brine) go to disposal wells (not sent to PW recycling process• PW & UPA streams are combined and treated with MF & NF in wastewater recycling process


Onshore Gas Gathering and Processing Plant Without Wastewater Recycling Process

River Water Intake

River Water Treatment

Water Distribution

Network

Sour Water

Stripper

BoilerWater

Treatment

Cooling Water Towers

Steam Injection: 2000 m3/d

Boiler Blowdown: 100 m3/d

Evaporation: 1000 m3/d

Cooling Tower Blowdown: 50 m3/d

Sour Water: 100 m3/d

Utility / Process Area Wash-down

Water Utility/Wash-down Water;100 m3/d

Steam Boilers

IX Brine: 100 m3/d

Produced Water:

2000 m3/d

Produced Water

Treatment

Wastewater Disposal

Wells

2100 m3/d

2200 m3/d

1050 m3/d

100 m3/d

100 m3/d

3450 m3/d

2450 m3/d

Produced Water; 2000 m3/d


Onshore Gas Gathering and Processing Plant With Wastewater Recycling Process

River Water Intake

River Water Treatment

Water Distribution

Network

Sour Water

Stripper

BoilerWater

Treatment

Cooling Water Towers

Steam Injection: 2000 m3/d

Boiler Blowdown: 100 m3/d

Evaporation: 1000 m3/d

Cooling Tower Blowdown: 50 m3/d

Sour Water: 100 m3/d

Utility / Process Area Wash-down

Water

Utility/Wash-down Water;100 m3/d

Steam Boilers

IX Brine: 20 m3/d (was 100 m3/d)

Produced Water:

2000 m3/d

Produced Water

Treatment

Wastewater Disposal

Wells

MF & NFWastewater Recycling Process

Retentate(Waste Stream):

210 m3/d

Permeate(Recycled Water):

1890 m3/d

210 m3/d

230 m3/d

1050 m3/d

100 m3/d

100 m3/d

1480 m3/d

480 m3/d

(was 3450 m3/d)

(was 2450 m3/d)


Examples of Offshore Scenarios (Generic/Hypothetical)

• Offshore Waterflood Process (MF)

• Offshore Sulfate Removal Membrane (SRM) Process (NF)

• Offshore Low Salinity Waterflood Process (NF & RO)

• Offshore Chemical-EOR Waterflood Process (NF)


Offshore Waterflood Process (MF)

Scenario: MF used as an alternative to multi-media filters for suspended solids removal; Seawater injection is to maintain reservoir pressure and improve oil production

Influent: Seawater

Influent Water Characterization:Flowrate: 100,000 BPDTSS: 2 mg/L

Treated Effluent Use: Injection into wells for reservoir pressure maintenance

Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 microns

Process: Seawater Lift Pumps

Coarse Strainers MF Deaeration

TowersInjection

Wells


Offshore Sulfate Removal Membrane (SRM) Process (NF)

Scenario: sulfate removal membranes (SRM) used as mitigation to prevent barium sulfate scale precipitation and/or reservoir souring; Seawater injection is to maintain reservoir pressure and improve oil production

Influent: Seawater

Influent Water Characterization:Flowrate: 100,000 BPDTSS: 2 mg/LSO4: 2,700 mg/L


Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 micronsSO4: < 40 mg/L



TowersInjection

WellsSRM(NF)


Sulfate Removal Membranes (SRM)

• Used to mitigate scale formation:

• Where oilfield reservoir formation water contains significant amounts of barium and/or strontium, injection of seawater can cause barium and strontium sulfate scale to be formed.

• These scales can become deposited in production pipe internals and may also have the effect of reducing reservoir permeability.

• Barium and strontium sulfate scales are difficult to remove since they are not easily dissolved.

• Uses nano-filtration membranes to remove sulfates from seawater

• Reduces seawater sulfate ion concentration from around 2,700 ppm to less than 40 ppm.

• May help mitigate formation souring by limiting the action of sulfate reducing bacteria (SRB)


Sulfate Removal Membranes (SRM) SRM Package 1 SRM Package 2

SeawaterFeed

(mg/L)

SRM Permeate

(mg/L)

% Reduction

SeawaterFeed

(mg/L)

SRM Permeate

(mg/L)

% Reduction

Sodium Na+ 11,200 10,690 5% 10,897 10,042 8%Potassium K+ 370 320 14% 460 419 9%

Calcium Ca2+ 400 330 18% 428 72 83%Magnesium Mg2+ 1,400 330 76% 1,368 68 95%

Chloride Cl- 19,750 19,000 4% 19,700 16,119 18%Bicarbonate HCO3- 140 20 86% 124 80 35%

Sulfate SO42- 2,650 40 98% 2,960 30 99%

Dissolved Solids TDS 35,910 30,730 14% 35,937 26,830 25%

Hardness (as CaCO3) 6,768 2,185 68% 6,706 460 93%


Sulfate Removal Membrane (SRM) Packages

90,000 BPD 250,000 BPD


Offshore Low-Salinity Waterflood Process (NF & RO)

Scenario: A combination of NF and RO used to partially desalinate and remove sulfate from seawater; Low-salinity seawater injection is to maintain reservoir pressure and enhance oil production

Influent: Seawater

Influent Water Characterization:Flowrate: 100,000 BPDTDS: 35,000 mg/LTSS: 2 mg/LSO4: 2,700 mg/L


Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 micronsTDS: < 4,000 mg/L SO4: < 40 mg/L

Process:Seawater

Lift PumpsCoarse

Strainers MF Deaeration Towers

Injection Wells

NF

RO


Offshore Chemical-EOR Waterflood Process (NF)

Scenario: NF used to soften seawater; Softened seawater is mixed with ASP for injection to maintain reservoir pressure and enhance oil production

Influent: Seawater

Influent Water Characterization:Flowrate: 100,000 BPDTDS: 35,000 mg/LTSS: 2 mg/LSO4: 2,700 mg/L

Treated Effluent Use: Mixing with ASP for polymer flood injection into wells for enhanced oil production

Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 micronsSO4: < 40 mg/LHardness: < 300 mg/L



TowersASP

MixingNF Injection Wells


Emerging Membrane Technologies

• Organo-phobic / Oleo-phobic MF (PW)

• Current MF is susceptible to fouling by suspended oil droplets in PW coating the membrane surface. Surface repulsion of oil droplets would enable less-frequent membrane cleaning cycles and less intensive pre-treatment for dispersed oil removal

• Subsea Seawater MF, NF & RO (on the Seafloor)

• Placement of seawater treatment processes at the location of subsea injection wells would enable farther off-sets from host facilities thereby allowing greater areal sweep of the reservoir, while also reducing weight and footprint on the host production facility

• Membrane Distillation (PW & Seawater)

• Membrane Distillation (MD) is a thermally-driven separation process, in which only vapor molecules transfer through a microporous hydrophobic membrane. The driving force in the MD process is the vapor pressure difference induced by the temperature difference across the hydrophobic membrane.


James Robinson, P.E.

Experience • Water Treatment

Engineering Advisor• Chevron (2011-2015)• BP (2000-2009)

• Water Management Engineering Consultant• Oxidane Engineering (2009-2011, 2015-present)• Cypress Engineering (1991-2000)

Professional • Professional Engineer• Society of Petroleum Engineers• Produced Water SocietyEducation • B.S. in Civil Engineering (1990)

Louisiana State University• M.S. in Engineering (1992)

Rice UniversityContact • [email protected]• (281) 384-3327

mailto:[email protected]?subject=

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